Field of the Invention
The present invention relates generally to linear slides and more specifically to machine tool ways and machine tool frames. The invention is a new and improved construction which integrates nesting linear slides into structural members. The invention enables a new method for the fabrication of machine tool components such as bases, tables, saddles, columns, or other sliding members. Due to its simplicity and extremely low cost the invention also relates to linear slides and guides for many other types of machines.
Description of the Prior Art
Ways are well known devices in the machine tool art and are used where accurate movement and positioning, high strength, and stiffness are all required to ensure precise contact of cutting or other tools with workpieces. Ways are used extensively to provide sliding alignment for various parts of machines which perform a wide variety of operations.
Dovetail ways or slides are a specific type of ways which are also well known in the machine tool art. They are used extensively in milling machines, lathes, and other machine tools. Achieving accurate alignment between dovetail ways and supporting frame members is a difficult and expensive part of machine tool manufacturing.
There exists a need, particularity in small machines, for a construction that provides strength, stiffness, and accurate alignment of machine tool ways with machine tool frames at a low cost.
Various aspects of this need have been recognized in the prior art. The prior art includes methods for attaching separately formed ways to structural members. U.S. Pat. No. 3,498,685 (Poplinski) describes a method for attaching separately formed ways to structural plates. U.S. Pat. No. 2,788,716 (McFerren) describes a machine tool frame and way construction for machine tools having opposed tool supports on aligned ways. These methods disclosed in the prior art for the mounting and positioning of ways on structural components require fastening and precise alignment of ways to structural members. This often makes their use on small or low-cost machines cost prohibitive.
U.S. Pat. No. 5,845,996 (Greubel) and U.S. Pat. No. 6,227,708 (Rixen) both describe linear guiding frames with fastening grooves or features used to attach bearings or sliding parts. U.S. Pat. No. 5,429,438 (Wood) describes a mechanical structure with sliding linear motion along an extrusion utilized in constructing a mechanical structure. The sliding linear motion is achieved through the use of a linear bearing assembly that mounts directly to the extrusion. Wood includes wear pads disposed between the linear bearing and the extrusion to prolong the life of the linear bearing and the extrusion.
The mechanical structure disclosed by Wood is not stiff enough or accurate enough to be used for most machine tool applications and many other applications where accurate guiding and positioning are required. In addition, Wood requires a separately designed support extrusion and linear bearing assembly, which increases the number of parts required to produce a sliding connection.